Pneumatic refuse material separation system

ABSTRACT

Light and heavy constituents of refuse material are separated by delivering the material through a tubular inlet into the upper portion of a vertical separating chamber to drop onto and past declumping means and then to a spreader which directs it to fall through an annular venturi throat. As the material descends it is subjected to upwardly moving air of substantial velocity to separate lighter constituents of the material and draw them off from the separating chamber above the discharge end of the inlet. Heavier constituents are collected from the lower portion of the chamber spaced below the spreader.

United States Patent [191 Mackenzie et al.

[ 1 Sept. 3, 1974 PNEUMATIC REFUSE MATERIAL SEPARATION SYSTEM [75]Inventors: Harold B. Mackenzie, Wheaton, 111.;

lngvar G. Anderson, Dunedin; William T. S. Montgomery, Jr.,Jacksonville, both of Fla.

[73] Assignee: New Life Foundation, Wheaton, ll].

[22] Filed: Jan. 29, 1973 [21] Appl. No.: 327,420

[52] US. Cl 209/3, 209/138, 209/150 [51] Int. Cl B07b 4/02 [58] Field ofSearch 209/138-141, 209/149, 150, 146, 3, 5, 28, 29, 36, 37; 241/D1G. 6

[56] References Cited UNlTED STATES PATENTS 71,536 11/1867 Quick 209/150431,313 7/1890 Ballard 209/139 A 940,469 11/1909 Middleton 209/150 X1,522,151 l/l925 Stebbins 209/150 2,009,729 7/1935 Falkiner 209/139 R X2,729,330 l/l956 Newirth 209/150 X 2,766,880 10/1956 Schaub et al.209/150 X 2,795,329 6/1957 Schaub 209/139 R Primary ExaminerFrank W.Lutte'r Assistant ExaminerRalph J. Hill Attorney, Agent, or Firm-Hill,Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [5 7 ABSTRACTLight and heavy constituents of refuse material are separated bydelivering the material through a tubular inlet into the upper portionof a vertical separating chamber to drop onto and past declumping meansand then to a spreader which directs it to fall through an annularventuri throat. As the material descends it is subjected to upwardlymoving air of substantial velocity to separate lighter constituents ofthe material'and draw them off from the separating chamber above thedischarge end of the inlet. Heavier constituents are collected from thelower portion of the chamber spaced below the spreader.

4 16 Claims, 2 Drawing Figures 3',asa.111

PATENIEBsEP 3:914

Fig. 2

PNEUMATIC REFUSE MATERIAL SEPARATION SYSTEM This invention relates tomaterials separation, and is more particularly concerned with apneumatic refuse material separation system. Refuse materials such asmunicipal garbage and trash, now generally collected withoutdiscrimination, present substantial problems in separation thereof forrecovery of reusable. raw products such as paper, glass and metals. Itis to the solving of these problems that the present invention isdirected.

An important object of the invention is to provide a new and improvedpneumatic refuse. material separation system.

Another object of the invention is, to provide a new and improved meansfor efficiently separating diverse materials such as municipal or otherrefuse for recovering reusable constituents.

A further object of the invention is tov provide anew and improvedpneumatic material separating system.

Other objects, features and advantages of the: invention will be readilyapparent from the. followingv description of certain preferredembodiments thereof, taken in conjunction with the accompanying drawingalthough variations andmodifications may be effected without departingfrom the spirit and scope of the novel concepts embodied in thedisclosure, and in which:

FIG. 1 is a fragmentary top plan view of a systemembodying features ofthe invention;

FIG. 2 is a vertical sectional detail view taken substantially 'alongthe line IIII of FIG. I.

Loose refuse material 5 such as municipal trash, and I garbage isdelivered as by means of an endless conveyor 7 into the upper end of atubular inlet 8 which is desirably provided with an upwardly flaringfunnel-like mouth head structure 9. Within the inlet-.8the material isguided to drop down into a downwardly opening separating chamber 10defined by means comprising acolumnar casing providing wall 11 ofsubstantial length about the chamber, with the inlet 8'ofsmallerdiameter and extending concentrically downwardly to a limited extentthrough and below a top closure 12 into the separating chamber. Suitableframe structure 13 supports the vertical chamber wall 11 and the inlet 8carried by the chamber wall through the top closure 12.

For breaking up descending clumped masses of the material to beseparated, declumping means 14. are provided adjacently below thedischarge end of the inlet 8. In a desirable construction, thedeclumping means 14 comprise a set of radial vanesv 15 disposed: invertical planes and of preferably triangular shape in elevation. Supportfor the vanes 15 is provided bymeans such as a vertical bar or rod 17which extends vertically concentrically through the inlet 8 and issuspended, preferably rigidly, from supporting means 18 such as aceiling or other supporting structure above the receiving head 9 of theinlet. In diameter, the suspension rod.

17 is as small as practicable for the purpose and throughout its lengthwithin the inlet the rodis smooth and free from obstructions onwhichmaterial might.

catch, so that the passage through the inlet is practically free fordropping of material to be separated downwardly therethrough into thechamber 10 toward the declumper 14. Each of the vanes 15 is fixedlysecured to the supporting rod 17 at anelongated hypotenuse and with thevanes radiating in uniformly spaced relation to a common diameter attheir convergent edge peaks approximately one-half that of the inletdiameter. In a desirable arrangement there are six of the vanes 15, asshown. Through this arrangement, the vanes 15 efficiently break-uplarger masses or clumps of adherent material, but avoid catching of thematerial thereon.

Within the chamber 10 the descending material is subjected to pneumaticseparation by forcing air upwardly through the material for therebycarrying off the lighter constituents of the material, such as paper.Preferably the separating air-flow is effected by means causing asuction primarily upwardly through the chamber 10 from the lower openend of the wall'casing 11-. For this purpose, a suitable blower 19 isconnected withanexhaust duct 20 leading from an exhaust throat 21communicating by way of a wide angle exit opening 22 with the upper endof the chamber 10 immediately below the top closure. 12 and at asubstantial height above the lower end of the inlet 8. Although at leastone exhaust opening and duct may beprovided, a plurality of such exhaustarrangements may beprovided' at circumferentially spaced intervals (FIG.1.) at the same or graduated elevations and providing for the samesuction velocity or graduated suction velocities, as may be preferred.

To enhance separating effect of the pneumatic column in the separatingchamber 10', velocity increasing means are provided, comprising aspreader and venturi member 23. For this purpose, the spreader 23 issupported in fixed suspended relation fromthe lower end of the rod17preferably coincident with the lower end of the declumper 14. On itsupper end the spreader 23 has a generally downwardly and radiallytapering spreader surface 24 which joins a reversely tapering conicalair deflecting undersurface 25, with the surfaces meeting at a perimeterof a diameter about the same as the diameter of the inlet 8. Between theperimeter of the spreader 23 and the surrounding portion of the chamberwall 11 is defined an annular venturi velocity increasing throat 27.Thereby descending material deflected into the venturi throat issubjected to high velocity separating air with an advantageous pressuredrop above the throat for large volume air lifting and tumblingof thedescending materials for separation of the lighter constituents whichare then sucked up the reduced cross-section chimney area between theinlet Sand the wall 11. Downward movement of the material to beseparated, and countermovement of the air and lifting of the lightermaterials is graphically shown by means of directional arrows. This airseparation is-enhanced by the flow path along the unconstrictedpassageprovided within the wall casing 'l l which provides a flow unobstructedexcept for the spreader'23", entirely down to the lower end outletopening from-the casing.

Constituents of the materials to be separated, which are heavier thanwill be lifted by the ascending air, drop down below the spreader 23 anddischarge from the separating chamber through preferably open lowerendprovided by the wall casing 11 and are collected as shown at 28 on meanssuch as a conveyor 29l for further separating action or for disposal.

Although only one of the separatorsaccording to the present inventionhas been disclosed, it will be understood that there may be as many ofsuch separators as necessary to handle any given volume of refuse, and

there may be batteries of the separators in series for multiple rawproduct separation. In such an installation raw products such as paper,glass and metals are segregated and collected, land fill refuse ispacked into transporting and dumping apparatus, and such refuse or trashas cannot be reused or recycled may be burned in an incinerator whichprovides heat for drying valuable raw products such as paper.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

We claim as our invention:

1. In a pneumatic refuse material separation system:

means defining a wall about a vertical separation chamber;

a tubular inlet through which material to be separated is received andwhich is of smaller diameter than the chamber and extends to a limitedextent downwardly within the upper portion of the chamber, with adischarge end of the inlet opening freely downwardly within the chamber;

means for supplying material to be separated into said inlet to droptherefrom through said discharge end downwardly into the chamber;

declumping means comprising a plurality of circumferentially spacededges adjacently below said discharge end and in the path of dischargingmaterial for breaking up descending adherent masses of material;

spreader means for receiving and spreading the descending materiallaterally below the declumping means and above the lower end of thechamber and defining an annular venturi throat with said wall;

means for effecting separating air-flow upwardly through said chamberand the venturi throat and past said declumping means and said inlet toseparate lighter constituents from said material; and

means for receiving heavier constituents from the lower portion of thechamber spaced below said spreader means.

2. A system according to claim 1, including a supporting rod extendingdown through said inlet and supporting said declumping meanslongitudinally therealong.

3. A system according to claim 2, wherein said declumping means comprisea set of radially extending circumferentially spaced generallytriangular vanes carried by said rod and providing said edges.

4. A system according to claim 3, wherein said spreader comprises amember supported by said rod at the lower end of said set of declumpingvanes.

5. A system according to claim 1, wherein said declumping meanscomprises a set of radially extending circumferentially spaced vanesextending to a diameter about one-half that of the diameter of saidinlet, said spreader means comprises a member which is about the samediameter as said inlet, and means supporting said declumping means andsaid spreader means concentrically relative to said inlet and to saidchamber.

6. A system according to claim 1, wherein said walldefining meanscomprise a vertical casing having a top closure through which said inletextends concentrically with respect to said chamber, said means forseparating air flow including an exhaust outlet in said casing ad acentto said closure and leading off laterally from the casing in the form ofa throat extending from a wide angle exit opening in the upper end ofthe casing, the throat having side walls which extend tangentially fromthe casing and converge toward an exhaust duct.

7. In a pneumatic refuse material separation system:

delivering material to be separated to the upper end of a tubular inletwhich projects down to a limited extent into the upper portion of aseparating chamber;

dropping the material from the lower end of said inlet onto a pluralityof circumferentially spaced edges of and past a declumper located asubstantial distance below said inlet and thereby breaking up descendingadherent masses of material;

dropping the material beyond the declumper onto a spreader and therebydirecting the descending material into a venturi throat defined betweenthe spreader and a casing wall about the separating chamber;

forcing separating air at substantial velocity upwardly through thechamber including said venturi throat and through the descendingmaterial and lifting separated ligher constituents of the materialupwardly past the declumper and inlet and out of an exhaust opening inthe upper portion of the chamber;

and collecting heavier constituents of the material from the lowerportion of the chamber below the spreader.

8. A system according to claim 7, including subjecting the descendingmaterial to substantial pressure drop in a space between the spreaderand the inlet and in the vicinity of the declumper.

9. In a pneumatic refuse material separation system:

means defining a wall about a cylindrical vertical separation chamber;

a tubular inle-t through which material to be separated is received andwhich is of smaller diameter than the chamber and extends to a limitedextent downwardly within the upper portion of the chamber, with adischarge end of the inlet opening freely downwardly within the chamber;

means for supplying material to be separated into said inlet to droptherefrom through said discharge end downwardly into the chamber;

a supporting rod suspended at its upper end above the point at whichmaterial is introduced into said inlet and extending concentricallydownwardly through the inlet with the lower end of the rod extendingsubstantially below the lower end of the inlet;

a spreader member suspended from the lower end of said rod a substantialdistance below and concentric with the lower end of said inlet and abovethe lower end of said chamber and being of substantially the samediameter as said inlet and of smaller diameter than said chamber walland having convergently related conical upper and lower surfaces, theupper surface providing a spreader surface and the lower surfaceproviding an air deflecting surface;

said surfaces meeting in annularly spaced relation to said chamber walland defining an annular venturi throat with said wall;

said separation chamber wall providing an air-flow passage which isunobstructed except for said spreader and is unconstricted entirely downto the lower end of the chamber which has a free outlet openingdownwardly therefrom; means for effecting material separating air flowupwardly through said chamber, through the venturi throat andpast saidspreader and then past said inlet, to separate lighter constituents fromsaid mate rial; and t means for receiving heavier constituents whichdrop from said outlet.

10. A system according to claim 9, wherein said walldefining meanscomprise a vertical casing having a top closure through which said inletextendsconcentrically with respect to said chamber, said means forseparating air flow including an exhaust outlet in said casing adjacentto said closure and leading off laterally from the casing in the form ofa throat extending from a wide angle exit opening in the upper end ofthe casing, the throat having opposite side walls which extend generallytangentially from opposite sides of the casing and converge toward anexhaust duct.

11. In a pneumatic refuse material separation system:

means defining a wall about a vertical separation chamber;

a tubular inlet through which material to be separated is received andwhich is of smaller diameter than the chamber and extends to a limitedextent downwardly within the upper portion of the chamber, with adischarge end of the inlet opening freely downwardly within the chamber;

means for supplying material to be separated into said inlet to droptherefrom through said discharge end downwardly into the chamber;

a supporting rod suspended at its upper end above the point at whichmaterial is introduced into said inlet'and with the lower end of the rodextending substantially below the discharge end of the inlet;

a spreader member suspended from the lower end of said rod below thedischarge end of said inlet and above the lower end of said chamber andbeing of as large diameter as said inlet but of smaller diameter thansaid chamber wall and having convergently related conical upper andlower surfaces, the upper surface providing a spreader surface and thelower surface providing an air deflecting surface;

said surface meeting in annularly spaced relation to said chamber walland defining an annular venturi throat with saidwall;

means for effecting material separating air flow upwardly through saidchamber and the venturi throat and past said spreader and said inlet toseparate lighter constituents from said material;

means for receiving heavierconstituents from the lower portion of saidchamber spaced below said spreader; and

declumping means comprising a plurality of circumferentially spacededges carried by said rod adjacently below said discharge end of saidinlet and above said spreader for breaking up adherent masses ofmaterial descending from said discharge end. 7

12. A system according to claim 11, wherein said edges are provided by aset of radially extending circumfercntially spaced vanes projecting to adiameter about one half that of the diameter of said inlet, and

said spreader at the meeting of said surfaces at the venturi throatbeing of a diameter about the same as the diameter of said inlet.

13. In a pneumatic refuse material separation system:

said inlet to drop therefrom through said discharge end downwardly intothe chamber;

spreader means for receiving and spreading the descending materiallaterally below said discharge end and above the lower end of thechamber and defining an annular venturi throat with said wall;

means for effecting separating air-flow upwardly through said chamberand the venturi throat and past said inlet to separate lighterconstituents from said material;

said separation chamber wall providing an air-flow passage which isunobstructed except for said spreader and is unconstricted entirely downto the lower end of the chamber which has a free outlet openingtherefrom;

means spaced below said outlet for receiving heavier constituents whichdrop through the upwardly flowing air past said spreader; and

declumping means comprising a plurality of circumferentially spacededges located adjacently below saiddischarge end ofsaid inlet and abovesaid spreader for breaking up adherent masses of material descendingfrom said discharge end. I

14. A system according to claim 13, wherein said edges are provided by aset of radially extending circumferentially spaced vanes projecting to adiameter about one. half that of the diameter of said inlet, and

said spreader at the meeting of said surfaces at the venturi throatbeing of a diameter about the same as the diameterof said inlet.

15. In a pneumatic refuse material separating system:

means defining a wall about a vertical separation chamber;

a tubular inlet through which material to be separated is received andwhich is of smaller diameter than the chamber and extends to a limitedextent downwardly within the upper portion of the chamber, 'with adischarge end of the inlet opening freely downwardly within the chamber;

means for supplying material to be separated into said inlet to droptherefrom through said discharge end downwardly into the chamber;

spreader means for receiving and spreading the descending materiallaterally below said discharge end and above the lower end of thechamber and defining an annular venturi throat with said wall;

means for effecting separating air-flow upwardly through said chamberand the venturi throat and past said inlet to separate lighterconstituents from said material;

said separation chamber wall providing an air-flow passage which isunobstructed except for said spreader and is unconstricted entirely downto the lower end of the chamber which has a free outlet openingtherefrom;

means spaced below said outlet for receiving heavier constituents whichdrop through the upwardly flowing air past said spreader;

said wall-defining means comprising a vertical casing having a topclosure through which said inlet extends concentrically with respect tosaid chamber;

said means for separating air-flow including an exhaust outlet in saidcasing adjacent to said closure and leading off laterally from thecasing in the form of a throat extending from a wide angle exit openingin the upper end of the casing; and

of the casing and converge toward an exhaustduct.

1. In a pneumatic refuse material separation system: means defining awall about a vertical separation chamber; a tubular inlet through whichmaterial to be separated is received and which is of smaller diameterthan the chamber and extends to a limited extent downwardly within theupper portion of the chamber, with a discharge end of the inlet openingfreely downwardly within the chamber; means for supplying material to beseparated into said inlet to drop therefrom through said discharge enddownwardly into the chamber; declumping means comprising a plurality ofcircumferentially spaced edges adjacently below said discharge end andin the path of discharging material for breaking up descending adherentmasses of material; spreader means for receiving and spreading thedescending material laterally below the declumping means and above thelower end of the chamber and defining an annular venturi throat withsaid wall; means for effecting separating air-flow upwardly through saidchamber and the venturi throat and past said declumping means and saidinlet to separate lighter constituents from said material; and means forreceiving heavier constituents from the lower portion of the chamberspaced below said spreader means.
 2. A system according to claim 1,including a supporting rod extending down through said inlet andsupporting said declumping means longitudinally therealong.
 3. A systemaccording to claim 2, wherein said declumping means comprise a set ofradially extending circumferentially spaced generally triangular vanescarried by said rod and providing said edges.
 4. A system according toclaim 3, wherein said spreader comprises a member supported by said rodat the lower end of said set of declumping vanes.
 5. A system accordingto claim 1, wherein said declumping means comprises a set of radiallyextending circumferentially spaced vanes extending to a diameter aboutone-half that of the diameter of said inlet, said spreader meanscomprises a member which is about the same diameter as said inlet, andmeans supporting said declumping means and said spreader meansconcentrically relative to said inlet and to said chamber.
 6. A systemaccording to claim 1, wherein said wall-defining means comprise avertical casing having a top closure through which said inlet extendsconcentrically with respect to said chamber, said means for separatingair flow including an exhaust outlet in said casing adjacent to saidclosure and leading off laterally from the casing in the form of athroat extending from a wide angle exit opening in the upper end of thecasing, the throat having side walls which extend tangentially from thecasing and converge toward an exhaust duct.
 7. In a pneumatic refusematerial separation system: delivering material to be separated to theupper end of a tubular inlet which projects down to a limited extentinto the upper portion of a separating chamber; dropping the materialfrom the lower end of said inlet onto a plurality of circumferentiallyspaced edges of and past a declumper located a substantial distancebelow said inlet and thereby breaking up descending adherent masses ofmaterial; dropping the material beyond the declumper onto a spreader andthereby directing the descending material into a venturi throat definedbetween the spreader and a casing wall about the separating chamber;forcing separating air at substantial velocity upwardly through thechamber including said venturi throat and through the descendingmaterial and lifting separated ligher constituents of the materialupwardly past the declumper and inlet and out of an exhaust opening inthe upper portion of the chamber; and collecting heavier constituents ofthe material from the lower portion of the chamber below the spreader.8. A system according to claim 7, including subjecting the descendingmaterial to substantial pressure drop in a space between the spreaderand the inlet and in the vicinity of the declumper.
 9. In a pneumaticrefuse material separation system: means defining a wall about acylindrical vertical separation chamber; a tubular inlet through whichmaterial to be separated is received and which is of smaller diameterthan the chamber and extends to a limited extent downwardly within theupper portion of the chamber, with a discharge end of the inlet openingfreely downwardly within the chamber; means for supplying material to beseparated into said inlet to drop therefrom through said discharge enddownwardly into the chamber; a supporting rod suspended at its upper endabove the point at which material is introduced into said inlet andextending concentrically downwardly through the inlet with the lower endof the rod extending substantially below the lower end of the inlet; aspreader member suspended from the lower end of said rod a substantialdistance below and concentric with the lower end of said inlet and abovethe lower end of said chamber and being of substantially the samediameter as said inlet and of smaller diameter than said chamber walland having convergently related conical upper and lower surfaces, theupper surface providing a spreader surface and the lower surfaceproviding an air deflecting surface; said surfaces meeting in annularlyspaced relation to said chamber wall and defining an annular venturithroat with said wall; said separation chamber wall providing anair-flow passage which is unobstructed except for said spreader and isunconstricted entirely down to the lower end of the chamber which has afree outlet opening downwardly therefrom; means for effecting materialseparating air flow upwardly through said chamber, through the venturithroat and past said spreader and then past said inlet, to separatelighter constituents from said material; and means for receiving heavierconstituents which drop from said outlet.
 10. A system according toclaim 9, wherein said wall-defining means comprise a vertical casinghaving a top closure through which said inlet extends concentricallywith respect to said chamber, said means for separating air flowincluding an exhaust outlet in said casing adjacent to said closure andleading off laterally from the casing in the form of a throat extendingfrom a wide angle exit opening in the upper end of the casing, thethroat having opposite side walls which extend generally tangentiallyfrom opposite sides of the casing and converge toward an exhaust duct.11. In a pneumatic refuse material separation system: means defining awall about a vertical separation chamber; a tubular inlet through whichmaterial to be separated is received and which is of smaller diameterthan the chamber and extends to a limited extent downwardly within theupper portion of the chamber, with a discharge end of the inlet openingfreely downwardly within the chamber; means for supplying material to beseparated into said inlet to drop therefrom through said discharge enddownwardly into the chamber; a supporting rod suspended at its upper endabove the point at which material is introduced into said inlet and withthe lower end of the rod extending substantIally below the lower end ofthe inlet; a spreader member suspended from the lower end of said rodbelow the lower end of said inlet and above the lower end of saidchamber and being of as large diameter as said inlet but of smallerdiameter than said chamber wall and having convergently related conicalupper and lower surfaces, the upper surface providing a spreader surfaceand the lower surface providing an air deflecting surface; said surfacemeeting in annularly spaced relation to said chamber wall and definingan annular venturi throat with said wall; means for effecting materialseparating air flow upwardly through said chamber and the venturi throatand past said spreader and said inlet to separate lighter constituentsfrom said material; means for receiving heavier constituents from thelower portion of said chamber spaced below said spreader; and declumpingmeans comprising a plurality of circumferentially spaced edges carriedby said rod adjacently below said discharge end of said inlet and abovesaid spreader for breaking up adherent masses of material descendingfrom said discharge end.
 12. A system according to claim 11, whereinsaid edges are provided by a set of radially extending circumferentiallyspaced vanes projecting to a diameter about one half that of thediameter of said inlet, and said spreader at the meeting of saidsurfaces at the venturi throat being of a diameter about the same as thediameter of said inlet.
 13. In a pneumatic refuse material separationsystem: means defining a wall about a vertical separation chamber; atubular inlet through which material to be separated is received andwhich is of smaller diameter than the chamber and extends to a limitedextent downwardly within the upper portion of the chamber, with adischarge end of the inlet opening freely downwardly within the chamber;means for supplying material to be separated into said inlet to droptherefrom through said discharge end downwardly into the chamber;spreader means for receiving and spreading the descending materiallaterally below said discharge end and above the lower end of thechamber and defining an annular venturi throat with said wall; means foreffecting separating air-flow upwardly through said chamber and theventuri throat and past said inlet to separate lighter constituents fromsaid material; said separation chamber wall providing an air-flowpassage which is unobstructed except for said spreader and isunconstricted entirely down to the lower end of the chamber which has afree outlet opening therefrom; means spaced below said outlet forreceiving heavier constituents which drop through the upwardly flowingair past said spreader; and declumping means comprising a plurality ofcircumferentially spaced edges located adjacently below said dischargeend of said inlet and above said spreader for breaking up adherentmasses of material descending from said discharge end.
 14. A systemaccording to claim 13, wherein said edges are provided by a set ofradially extending circumferentially spaced vanes projecting to adiameter about one half that of the diameter of said inlet, and saidspreader at the meeting of said surfaces at the venturi throat being ofa diameter about the same as the diameter of said inlet.
 15. In apneumatic refuse material separating system: means defining a wall abouta vertical separation chamber; a tubular inlet through which material tobe separated is received and which is of smaller diameter than thechamber and extends to a limited extent downwardly within the upperportion of the chamber, with a discharge end of the inlet opening freelydownwardly within the chamber; means for supplying material to beseparated into said inlet to drop therefrom through said discharge enddownwardly into the chamber; spreader means for receiving and spreadingthe descending material laterally below said discharge end and above thelower end of the chamber aNd defining an annular venturi throat withsaid wall; means for effecting separating air-flow upwardly through saidchamber and the venturi throat and past said inlet to separate lighterconstituents from said material; said separation chamber wall providingan air-flow passage which is unobstructed except for said spreader andis unconstricted entirely down to the lower end of the chamber which hasa free outlet opening therefrom; means spaced below said outlet forreceiving heavier constituents which drop through the upwardly flowingair past said spreader; said wall-defining means comprising a verticalcasing having a top closure through which said inlet extendsconcentrically with respect to said chamber; said means for separatingair-flow including an exhaust outlet in said casing adjacent to saidclosure and leading off laterally from the casing in the form of athroat extending from a wide angle exit opening in the upper end of thecasing; and said throat having opposite side walls which extend from thefull width of said opening and generally tangentially from oppositesides of the casing and converge toward an exhaust duct.
 16. A systemaccording to claim 15, including at least one more exhaust outlet insaid casing adjacent to said closure and to said first mentioned exhaustoutlet and leading off laterally from the casing in the form of a throatextending from a wide angle exit opening in the upper end of the casingand having opposite side walls which extend generally tangentially fromopposite sides of the casing and converge toward an exhaust duct.